Origin begins construction of four-hour battery addition to help replace Australia’s biggest coal generator

Origin Energy has announced the start of construction of the second stage of its Eraring battery, which will end up being one of the biggest in the country as it finally accelerates work to replace Australia’s biggest coal generator at the same site.

The first stage of the Eraring battery, a 460 MW, two and a bit hour (1,073 MWh), is already under construction and is expected to be on line by the end of the 2025, soon after the date the coal generator had been flagged to close.

The second stage of the battery – at 240 MW and 1,030 MWh – with a smaller connection point but with longer storage – is expected to come on line in early 2027, the year that the coal generator is now scheduled to close under an extension deal underwritten by the state government – although it may stay open longer.

“Today is another important step in Origin’s transformation of the Eraring site so it can continue contributing to the reliability and security of energy supply in this region and support the ongoing growth of variable renewable energy in the grid,” Origin Energy CEO Frank Calabria said in a statement.

“Large scale batteries like the one we are developing at Eraring will play an important role in the energy transition, charging when renewables are abundant and discharging when needed, such as during the evening peak.

“This is just one way Origin is pursuing its ambition to lead the energy transition.”

The $1 billion project will have combined storage of more than 2 gigawatt hours when complete, making it one of the biggest in the country.

Battery storage facilities have leaped in size from around 150 MWh at the first Tesla big battery at Hornsdale, to 450 GWh at the Victoria Big Battery and 1,650 MWh at the soon to be commissioned Waratah Super Battery, which is located at the site of the former Munmorah coal fired power station not far from Eraring.

The biggest battery project in Australia, the 2,240 MWh Collie battery, is also well under construction near the site of another shuttered coal fired power station in Western Australia and this week opened its 867 MWh first stage.

Big batteries are operating, under construction, or planned, at the sites of the Hazelwood, Loy Yang, Liddell, Bayswater, Mt Piper, Stanwell, Tarong, Kogan Creek and Callide coal fired power station sites.

A number of other battery projects are also under construction, or soon to begin, of equal size, but it will be trumped as the biggest by a 2,200 MWh eight hour battery in norther NSW that will likely be completed around the same time.

The local member for Lake Macquarie, Greg Piper, said Eraring had been a source of many jobs supporting families and the local economy.

“The power station with its connection to the power grid is perfectly positioned to be part of the energy future of the state,” he said. “I’m keen to see that continue along with the ongoing contribution to the local economy long after coal generation ends. Today’s announcement is another step on that journey.”

The battery equipment will be supplied by Finnish technology group Wärtsilä, believed to be its largest battery contract in the world. It has also supplied AGL’s 250 MW, 250 MWh Torrens Island battery in South Australia.

The balance of plant will be delivered by Enerven, a subsidiary of SA Power Networks, and Lumea (the commercial arm of Transgrid) will complete the dedicated HV substation works.